As an example of a method for setting identification information in a network having a plurality of devices connected thereto, one disclosed in Japanese Unexamined Patent Application, Publication No. 2004-193643 (PTL 1) is known in the related art. PTL 1 discloses a technique in which a terminal to be newly connected transmits a connection request message containing provisional identification information to other terminals and sets the provisional identification information as its identification information unless it receives, as a response thereto, a conflict message indicating a terminal having identification information conflicting with the provisional identification information from the other terminals that have received the connection request message.
In addition, for example, Publication of Japanese Patent No. 3549676 (PTL 2) discloses a technique in which a central unit regularly transmits an allocation request message for identification information to a plurality of terminals connected thereto via a network and allocates new identification information to a terminal newly connected to the network if the central unit receives a reply to the allocation request message from the new terminal.